can limit message characters in muc??
can limit nick characters in muc ??
can filter bad nick such as subject and body ??
can make an ip in blacklist can’t join muc ??
can make s2s connection to another server open on client and block on muc??
No, you can’t. I mean, with the default Openfire installation. Of course, anything is possible if you modify the source and create your own server version.
can make limit to join muc from admin server only no owner room??
Not sure i understood you. You can block room creation, so only admin could create them in Admin Console. Check Group Chat Settings - Room Creation Permissions.
can make transport with skype ??
Skype is a closed protocol, so no easy transport integration. I haven’t heard about Skype transports for Openfire, though there are probably some Skype transports. But i think most of the scenarious still require to have Skype running on a computer to be able to connect to Skype network.